The electrical systems in automotive vehicles include connectors (e.g., high-voltage connectors) which are electrically connected by inserting a male connector into a female connector. In general, a male connector includes a male connector terminal and a female connector includes a female connector terminal.
FIG. 4 illustrates a coupled state of a male connector terminal and a conventional female connector terminal, in which FIG. 4(A) illustrates a cross-sectional view taken along a plane in an insertion direction of the male connector terminal and FIG. 4(B) illustrates a cross-sectional view taken along a plane in a direction normal to the insertion direction of the male connector terminal.
A female connector terminal 50 includes a conductive portion 54, ribs 56, and an elastic member 58. The ribs 56 can contact a conductive surface of the male connector terminal 52 when the male connector terminal 52 is coupled with the female connector terminal 50. The elastic member 58 faces the ribs 56. The conductive surface of the male connector terminal 52 is a surface on which a metal plating (e.g., tinning) is applied. A clearance is provided between the ribs 56 and the elastic member 58 to support the male connector terminal 52. If the conductive surface of the male connector terminal 52 contacts the ribs 56 of the female connector terminal 50, an electric path connecting the male connector terminal 52 and the female connector terminal 50 can be formed.
As discussed in Japanese Laid-Open Patent Application No. Hei 8-78081, if a female connector terminal includes an elastic member (e.g., a plate spring), a specific portion of the female connector terminal is not worn excessively when the male connector terminal is frequently inserted and disengaged. The female connector terminal can provide superior insertion/disengagement durability.
However, if a female connector has such a above-described female connector terminal, the pressing force exerted on the male connector terminal is applied only in the up-and-down direction. Therefore, a small sideways sliding movement may occur at a contact portion between the male connector terminal and the female connector terminal when an engine or automotive vehicle body vibrates, or when a thermal expansion or a thermal shrinkage occurs due to temperature changes or the like. In such cases, a small sliding movement at the contact portion between the male connector terminal and the female connector terminal induces friction on the conductive surface of the male connector terminal, i.e., the surface on which the metal plating (e.g., tinning) has been applied, and forms a metal oxide (e.g., tin oxide) on the conductive surface.
As described above, if a metal oxide is formed on the conductive surface of the male connector terminal, the formed metal oxide increases the contact resistance at the contact portion between the male connector terminal and the female connector terminal, and may possibly also increase the temperature at the contact portion.
Generally, the substrate of the female connector holding the female connector terminal is made of a synthetic resin material having appropriate insulation properties. Therefore, if the temperature at the contact portion between the male connector terminal and the female connector terminal increases excessively, the synthetic resin material may soften leading to damage of the female connector.
If the connector is a high-voltage type subjected to large current, the board thickness of its male connector terminal is thick and the rigidity of its male connector terminal is high. Therefore, to reduce an insertion load required when the male connector terminal is inserted into the female connector terminal, a predetermined clearance is required between both edges of the male connector terminal and an inner surface of the female connector terminal.
Hence, an object of the present invention is to provide a female connector terminal and a female connector that can suppress a slide movement of a male connector terminal relative to a female connector terminal and can reduce the contact resistance at a contact portion between the male connector terminal and the female connector terminal.